Fluid pressure governing mechanism



, 1930 2 Sheets-Sheet 1 MN v Nov. 15, 1932. K. BAUMANN ET AL FLUID PRESSURE GOVERNING MECHANISM Filed July 18 |NvENToR5 KHELBMMHNH' nur:

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ATTORNEY Nov. 15, 1932. K. BAUMANN ET Al.

FLUID PRESSURE GovERNING MECHANISM Filed July 18, 1930 2 Sheets-Sheet 2 IN`VENTOR Kmaummm A ALE, JQLLEY.

im w wlTN ESS ATTORNEY Patented Nov. 15, 1932 UNITED STATES PATENT OFFICE KARL BAUMANN,` OF BARNFIELD, URMSTON, AND JOHN ERNEST JOLLEY, F STRET- `FORI), MANCHESTER, ENGLAND, ASSIGNORS TO WESTINGHOUSE ELECTRIC AND MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA FLUID PRESSURE GOVERNING MECHANISM Application filed July 18, 1930, Serial No. 468,918, and in Great Britain August 26, 1929.

The invention relates to means for governing steam turbines or other engines wherein it is required to ope-rate a regulating valve or the like (hereinafter referred to as the governor valve) in accordance with variations in speed. The invention concerns particularly governing means of the kind in which a centrifugal or equivalent type -of governor which is responsive to variations in i0 speed, is arranged to control the operation of a fluid pressure system by which the operation of y one or more governor valves is effected. p V

The object of my invention is to provide improved governing means of the kind referred to, which will be reliable and effective in operation and particularly advantageous for use in cases where the governor valves are so disposed with respect to the governor as to render direct connection therebetween inconvenient, or wherein it is desired to operate a plurality of governor Vvalves simultaneously or in a desired sequence.

Accordingly the invention provides improved governing means of the kind referred to wherein the governor is adaptedto operate a pilot valve which controls the application of iuid to a piston member of a fluid pressure relay which is operatively associated with the pilot valve so as to reset same when the pressure upon said piston member attains a value proportional to; the displacement of the pilot valve from a given position, while the governor valve is also adapted to be operated by an operating piston, the application of pressure to which is controlled by a relay device responsive to andv in accordance with the pressure upon the piston member aforesaid. Y l n The improved governing means may conveniently be considered as comprising two iuid pressure relay devices, one, which may be termed the translator unit,v being associated with the governor pilot valve and adapted to control the pressure in a. iuid system in accordance with the speed of the turbine or other engine in question while the other relay device, which may be termed the sympathetic uniti, controls the voperation of the governor valve in accordance with the pressure in said `fluid system2 thereby establishing a definite relationship between the speed and the position ofthe governor valve. Any desired number of governor valves may be controlled by a corresponding number of sympathetic units all associated with the same fluid system. Furthermore, vthe opera-V Y tion of a number of governor valves may be caused to take place simultaneously or in a desired sequence by Vsuitably shaping the ports of the relay devices.

The invention is illustrated diagrammatically by way of example in the accompanying drawings in which:

Fig. l shows a general arrangement of relay devices constituting translator and sympathetic units, together with auxiliary elements in one construction of thejinvention. Y

Fig. 2 shows a modified form of the translater unit and Fig. 3 shows a modified form of the sympathetic unit.

Referring to the drawings, the relay device constituting the translator unit 41, as shown in Fig. l, comprises a` piston member l, hereinafter'referred to as the variable pressure piston7 which 'is-spring loaded by the spring 2k and is formedL as a piston valve slidable within a sleeve 3 vprovided with ports 3b. The latter is loaded by a spring L Land 80 provided with a piston portion to which pressure may be applied as' hereinafter described in order to move said sleeve in opposition toits spring 4l. The sleeve 3 is slidable in the relay Vcasing 6 and at one end is 85 connected with a rod 7 passing. tothe eX- terior of the casing and connected to a compensating lever 8 of a Vpilot valve 9.

The pilot valve 9, which cooperates with a sleeve 12'having ports 12a, may be of usual type, connected as shown in Fig. 2,et`o the compensating lever 8 at an intermediate point 14 thereof,Y the ends' of the lever being pivoted to the relay sleeve 3, 5 as above stated and at 13 to the governor spindle l0 respectively; or the pilot valve may be directly connected to the governor spindle l0 as shown in Fig. l, in whichcase the compensating lever 8 is pivoted about a fixed pivot 1l and operates upon a slidable sleevev 12 100 provided with ports 12a and cooperating with the pilot valve. The advantage afforded in the construction shownin 1 is the facility of adjustment by adjusting the position-of the fixed-pivot 11', which is V'accoii'iplished by a lever 16 'pivoted to a fulcrum 17 'and operated by a hand wheel 15. e y e The relay device constituting the: sympathetic uni'tpll2 Amay be substantially similar to that of the translator unit 41, with lthe eX` ception that the ported vsleeve member 3a is not formed with a pistonvportion. It is, however, connected with a power piston 18 for operating the governor valve 19 through the intermediary of a lever 20, which also Serves as a compensating lever for the relay and is pivotally connected withv the power piston 18, the governor valve 19, the sleeve member of the relay 3, and a fixed pivot 21.

The casings of the pilot valve and the relays are divided into pressure and drainage portions and connected with pipe lines as shown, appropriate for the operation of the system in the following manner?- Upon a decrease in speed, the governor spindle falls and moves the pilot valve 9 which admits fluid from a high pressure source such as a pump 3l to a compartment 22 of the translator relay casing by way of a pipe 35, a valve 30, and pipes 36 and 37. This compartment is in direct communication with a similar compartment 23 of the sympathetic relay casing by means of a pipe 38. The fluid pressure thus created in said compartments acts upon the variable pressure pistons 1 and 1a of both relays so asto move saine in opposition to their springs 2 and 2q; and thereby uncover the ports 36 of their associated sleeve members 3 and 3a. This causes, in the case of the translator unit 41, the piston portion 5 of the sleeve member 3 to be exposed to fluid from-the high pressure source, whereby the sleeve is moved until its ports 36 are again covered by the variable pressure piston 1; at the same time the sleeve 12 of the pilot valve 9 is moved by the compensating lever 8 so as to tend to reset the pilot valve, i. e. to bring the pilot valve sleeve 12 into a position in which the pilot valve is again closed. rlhe amount of movement of the pilot valve sleeve necessary for resetting depends upon the distance which the valve has moved, which in turn depends upon the change of speed of Athe governor. Hence the supply of pressure fluid to the variable pressure piston 1 of the translator unit 41 will not be cut off by closure of the pilot valve 9 until both said piston 1 and the sleeve member 3 associated therewith have moved a distance corresponding to the position of the pilot valve, that is corresponding to the governor speed. rlhe fluid pressure acting upon the variable pressure piston 1 and opposed by the pressure of the spring 2 thereon will thus be brought to and maintained to a value corresponding to the governor speed.

rl`he fluid pressure thus determined is also transmitted to the piston 1a of the sympathetic relay 42,'so that the movement of this piston is falso proportional to the governor spe ed. 'Moreoven movement of this piston 1a serves to establish communication between 'the high pressure source and a power cylin- 'der 24 `of the governor kvali/'e 19 so that the latter is 'moved in the opening direction untilh'its movement, transmitted by the compensating lever to the sleeve member 3a of the sympathetic relay 42, resets the latter and prevents the supply of further pressure fluid to the power cylinder 211. ln `this way the movement ofthe governor valve 19 is made proportional to the governor speed.

Should the governor speed increase, the governing arrangement acts in the reverse manner, permitting the pressure fluid to cape via the drains 25 and 25a until the opening of the governor valve 19 is again adjusted to the speed.

The construction ofthe relays may be varied without altering the principle of action thereof. In Fig. 3, for example, there is shown a. sympathetic relay 426 of modified construction. ln this case, the pressure responsive piston 16 controls a separate pilot valve 26, instead of being itself formed as a pilot valve as in the case of a piston meinber la in Fig. 1. The pilot valve 26 controls the application of fluid pressure to a power piston 186 which actuates the governor valve 196, and it is connected to the piston 16 and the piston 186 by means of a compensating lever 206. The piston 16 is biased upwardly by a spring 26.

The operation of the sympathetic relay 426 shown in Fig. 3 is as follows: Upon an increase in pressure conveyed from the translator unit through the conduit 38, the piston 16 is depressed against the force of the spring 26 and lowers the pilot valve 26. The latter admits fluid pressure to raise the piston 186, moving the valve 196 in opening direction. As the piston 186 moves upwardly, it raises the pilot valve 26 through the lever 206 until it is restored to cut-oft position. Upon decrease in pressure, conveyed through the conduit 38, the spring 26 raises the piston 16, the latter raising the pilot valve 26 through the lever 206. The pilot valve 26 causes a downward movement of the piston 186, and closing movement'of the governor valve 19,6. The pilot valve 26 is returned to cut-off position by the downward movement of the piston 186 through the lever 206.

The :tree end a of the pipe 35 may .lead 'to a similar governor valve gear and sympathetic unit on No. 2 steam chest, the pipe 38a being also connected thereto. The pipe 39 leads from the valve 30 to emergency valve mechanisms of which there may be one for llU veach steam chest. The emergency valves function if the turbine speed rises above a resulting reduction of oil pressure causes the` emergency valves to be shut. v

`A manual device is fitted which may be used both for tripping and resetting the emergency valve operating gear. The hand lever 31, on being lifted releases the catch 28 by means of the pin 32 and allows the hammer 29 to open the valve 30. To reset the gear, the hand lever 31 is moved downwards when the pin 32 pulls the hammer 29 upwards and allows the valve 30 to resume its normal position. It will thus be seen that when set the hand lever 3l is only operative to trip the device and after tripping it is only operative to reset the device.

It will be evident that a governing arrangement such as described above posseses a number of highly advantageous qualities. No mechanical connection between the governor and the valve which it regulates is required, so that these appliances may be disposed in any position that may be desirable and their operation will not be interfered with by eX- ternal iniiuences. Also the movement of the governor valve in response to a change of speed may be made very promptly since the parts are mostly of light construction, and in particular the variable pressure pistons which determine the operation of the remainder of mechanism may b-e entirely free to move against the action of their springs and need not be called upon to move any other member. The system also is not affected by variations in the forces necessary to operate the governor valve.

It will further be observed that the piston member which operates the sleeve of the translator relay may be of relatively small dimensions and require only a small amount of fluid to effect its operation, whereas the power piston of the/governor valve which also resets the sleeve member of the sympathetic relay requires a greater force or a larger quantity of fluid for its operation. The resetting of the two sleeve members may, however, be arranged to take place in synchronism by suitably proportioning the ports which control the flow of fluid acting upon said pistons. Hunting in the govern-or system may thus be prevented.

The attainment of the degree kof synchronism necessary for satisfactory governing is facilitated by the adoption of negative lap on the various relay valves, the effect of which is to establish unidirectional flow of fiuid through the component partsl of the gear, thus avoiding oscillations which might be set up by fluid alternating in direction.

Chokes may be fitted in the inlets or drains to the relays or pistons for the purpose of damping out undesiredvibrations.

While we have shown our invention in two forms, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various other changes and modifications without departing from the spirit thereof, and we desire, therefore, that only such limitations shall be placed thereupon as are imposed by the prior art or as are specificallyhset forth in the appended claims.

at we claim is 1. A governing mechanism for the admission valve or valves of a prime mover comprising the combination of means roviding an enclosed space for a regulating uid pressure, a pilot valve for controlling said pressure, speed-responsive means for actuating the pilot valve, a fluid pressure relayfor kresetting the pilot valve when the regulating fluid pressure acquires the value called for by the speed-responsive means comprising an opf erating piston connected to the pilot valve, a pilot valve for the operating piston and means responsive to the regulating fluid pressure for controlling the last-mentioned pilot valve, and means responsive to said regulating fluid pressure for controlling the admission valve or valves.

d' 2. A governing mechanism according to claim l in which the pilot valves include sleeves formed with ports having negative laps for the purpose of avoiding oscillations in the regulating fiuid pressure.

In testimony whereof-,rwe have hereunto( subscribed our names this 1st day of July,

KARL BAUMANN. JOHN ERNEST JOLLEY.

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